Surface grinding machine



D86. 10, 1946. J 5 BLOOD 2,412,199

I SURFACE GRINDING MACHINE Filed Nov. 2, 1945- INVENTOR.

JOEL S. BLOOD I ATTORNEY Patented Dec. 10, 1946 .ZYfUNITE STATESorrlcrsv SURFACE GRINDING MACHINE Joel s. Blood, San (and, camApplication November 2, 1945, Serial No; 626,418 (01. 51-241) (Grantedunder the act of March, 3', 1883, as amended April 30, 1928; 370 0.G..-757) Claims.

- This invention relates to grinders and more particularly to mountingstherefor.

Objects of the present invention are to provide for the accurategrinding of marginal edge portions' of'opening's in walls, partitions,bulkheads and other members having openings therein; to provide animproved grinder for reducing portions' of members surrounding openingstherein to a predetermined plane; to provide an improved mounting forgrinders adjustably embracing bounding edge portions of openings inmembers to be ground; to provide a mountingior grinders accuratelyrestricting the movement of the grinders to predetermined planes ofmovement; to provide a grinder mounting capable of restraining grindermanipulation to. circular paths of predetermined radii; to provideamounting for a portable grinder permitting convenient manipulation ofthe grinder while the grinding means ismaintained in apredeterminedplaneof movement; and to provide improved elements andarrangements thereof in a 'mountingof the char-. acter and for the,purposes set forth.

In accomplishing these and-other objects of thepresent invention, I haveprovided improved details of structure, the preferred form of which isillustrated in the accompanying drawing, wherein the simple figure is-aside elevational view'oi the improved grinder 'and mounting embodyingthe features of the present invention, part of the device being shown incross-section.

Referring more in detail to the drawing:

1 indicates a member having an opening 2 formed therein, the boundingedge portions-of saidopening'. being a surface required to be ground. I

A spider member 3 having a-central body portion 4 and radially extendedleg portions 5 is positioned within the opening 2. Stud bolts 6 arescrew threadedlyengaged to the outer end portions of the legs 5 so as tobe radially extensible. The spider member 3 is secured in the opening 2by rotating the stud bolts 6 to engage the surrounding member I. Asocket 1 is formed in the ce'ntral body portion 4 of the spider3.

A ball-shaped element 8 having a screw threaded opening 9 formed thereinis positioned within the socket I. Retaining plate I0 is secured as at Hto the spider member 3 to retain the ballshaped element 8 in place.

A pivot post [2 is screw threadably engaged within the opening Set theball element 8. To maintain the pivot post securely in engagement withinthe ball 8, a locking means is provided as atl'3'l f The pivot post I2is provided with-a male screw threaded portion M at its extended endportion. The pivot post mounted on the ball J8 isthereby swivelly.engaged with the spider 3. To control the position of the pivot post 12,a levelling plate I5 is secured to the pivot post in a 'circum'jacentposition. Stud bolts l6 arescrew; threadably engaged within thelevelling plate l5 in a position to engage the spider member 3'and bytheir adjustment, position the levelling plate and thus the pivot postl2 in relation thereto.

A roller bearing I! having an inner'race l8, rollers l9 and outer race20 is mounted on the ivot-post by the screw threadedengagement: of theinner race I8 on the male screw threaded portion I4. The spacedrelationship between the bearing l1 and the spider 3 is adjustable byscrewing the inner race of the bearing 18 on the pivot post l2. To lookthe bearing H in place in adjusted position," the lock nuts 2| and 22are tightened against the bearing 11, the lock nut 22 being providedwith a depending frusto-conical portion to assistin positioning theinner bearing race I8. To provide greater security the nut 2| is slottedas at 23. A stud'bolt 24 is engaged within the locking nut 21 so as tocompress the slot portion 23 and jam the'locking nut. A lubricatingopening 25 is provided through the outer race 20 of the bearing 11.Bearing seals 26 are provided to retain lubricant within the bearing.

A rigid armmember 21 is secured to the outer race;20 of the bearing I!as at 28 in a radially extended position. The arm member is secured soas to rotate about the pivot post I2 in a plane of movementsubstantially at right angles to the pivot post.

A screw threaded opening 29 is formed in the outer end portion of thearm memberZ'l and a bearing'supporting element 3!] is screw threadedlyengaged in the arm. A roller bearing 3| having an inner race 32, ballbearings 33, and outer race 34 is mounted on the outer extended endportion of the arm member 21 by the supporting" element 30. A spacer 35is interposed between the inner race 32 and the arm member 2'1. A collar36 embraces the outer race 34 of the bearing 3| an inner flange portion31 thereof extending between the outer race and the arm member 21 Anannular plate 38 is positioned circumjacent the supporting element 30and is secured to the collar 36 by screw threaded means as at 39.Thecollar 36 and plate 38 tightly embrace the outer race 34. An armextension 40 is secured to the collar'36 as at 4| so as to pivot withthe collar on the bearingsupporting element 30 in a plane substantially;

parallel to the plane of rotation of the arm member 21.

It is sometimes desirable to lock the articulated joint so that the arm21 and extension 40 are rigidly connected. To this end, socket openings42 are formed in the collar 36 on the surface thereof 'facing'the armmember-21in a circular pattern arranged co axially to the pivot centerof the articulated joint. A receiver 43 is formed in the arm member 21in spaced relationship to the sockets 42. A locating pin 44 ispositioned Within the receiver 43. The pin 44 has a spring engag ingshoulder 45 and a knurled head 46 formed thereon. A spring 41 ispositioned. within the receiver 43 so as to bear againstthe shoulder-45.A spring keeper 48 is screw threadedly engaged in the opening 43circumjacent the pin 44 so as to retain the spring 41. To maintain thepin in a disengaged position when it is desired to do so,-

a receiving opening 49-is formed in the pin 44 and a locking pin 58engaged therein to hold the pin 44 in a retracted position.

An opening is formed in the outer end portion of the extension 48 havinga flange portion 52 inwardly disposed relative to the opening. A

gear housing 53 is fitted within the opening 5| so as to rest upon theflange portion 52. A bearing receptacle portion 54 is formed in thehousing 53. A ball bearing having an inner race 55, ball bearings 56,and an outer race 51 is mounted within the receptacle 54 by theengagement of the outer race therewith. To maintain the bearing inposition, an annular bearing keeper 58 is screw threadedly secured tothe housing. 53 as at '59, the shoulder 52 being embraced by thecooperative action of the housing 53 and the bearing keeper 58.

A shaft 60 having a pinion gear portion 6|, a

- bearing engaging shoulder 62, a screw threaded portion '63, and agrinder mounting portion 64 is rotatably mounted in the inner bearingrace 55. A bearing lock nut 65 is screw threadedly engaged to thethreaded portion 63 in cooperation with the shoulder 62 to embracetightly the inner bearing race 55. A jam nut 66 is tightened against thebearing lock nut 65. A grinding wheel 61 is mounted on the mountingportion 64 of the shaft 60. Agrinding wheel washer 68 and a jam nut 68are employed to secure the grinding wheel 61 in place. mounted withinthe housing 53 to cooperatively engage the gear portion 6|. A pin 1| isemployed to rotatably mount the gear 18 within the housing '53 Oman axisof rotation substantially at right angles to the axis of rotation of thegear portion 6|. A shaft 12 having a pinion gear portion 13, abearingembracing shoulder 14, a screw threaded portion 15, and a malecoupling portion 16 is mounted within the housing 53 in a positionengaging the pinion gear portion 13 with the opposite face of thebevelled gear 18 from that engaged by the bearing portion 6|. the axisof rotationof the shaft 12 being substantially at right angles to theaxis of rotation of the gear 10. A roller bearing 11 is employed tomount the shaft 12 within the housing 53. An annular bearing retainingplate 18 is secured tothe housing 53 so as to bear against the outerrace of thebearing 11 and so maintain the bearing in position. A looknut E9 and a jam nut 80 are screw threadably engaged to the shaft 12 asat 15 in coopera tion' with the shoulder 14 to tightlyembrace. the innerraceof the bearing 11.

The gear portion 6|, the gear and the gear portion 13 are cooperativelyengaged to comprise A double faced bevelled gear 10 is 4 a universalcoupling ermitting swivel movement of the shaft 12 in relation to theshaft 88 without interrupting the communication therebetween. To permitthis freedom of motion it has been found necessary to sever the housing53 as at 8|.

The severed housing at 8| is provided with cooperatively engaged tongueand groove portions to guide the movement of one portion of the housing53 on the other. Rotation of the housing in the plane of the'arm member21 and extension 40 is permitted by the movement of the housing 53 andthe keeper 58 within the opening 5|.

A-driving spindle of a conventional prime mover, not shown, is indicatedat 82.

Toconnect the driving spindle 82 to the connecting portion 16 of theshaft 12, coupling elements 83 and 84 are provided. The coupling 83 isscrew threadedly engaged to the male coupling portion 16. The coupling84 is screw threadedly engaged to the spindle 82. The coupling 83 has arecess 85 formed in the end thereof. The coupling 84 has a projectingstud portion 86 formed on the end thereof. The stud 86 is engaged withinthe opening 85. To maintain this engagement a taper pin 81 is passedthrough juxtaposed open ingsin the coupling 83 and the stud 86. The stud86 is madeof a diameter slightly smaller than the opening 85 in which itengages. This difierence in size imparts a flexibility to the'couplingof the prime mover to the shaft 12.

A housing 88 for the connection of the spindle 82 to the shaft 12 isscrew threadably engaged to the housing 53.

Operation The operation of a grinder constructed as described is asfollows:

The spider 3 is positioned within the opening 2 and locked in place byrotating the stud bolts 6 outwardly to engage the member The spider 3ispreferably secured in a plane substantially parallel to the surface ofthe member to be ground, the pivot post |2 being positionedsubstantially in the center of the opening 2.

The pivot post |2 being swivelly supported in the spider member 3 bymeans of the ball element 8, said pivot post I2 is positionedsubstantially at right angles to the surface of the member to be groundby adjusting the stud bolts "5 to secure the levelling plate I 5 inselected spaced relationship to the spider 3.

The inner race l8 ofthe bearing I1 is rotated on the pivot post |2 toadjust the height of the grinding wheel 61 supported thereby. The locknut -2| is tightened into place and secured by tightening the stud bolt24. The lock nut 22 is also tightened into place, its conical portionengaging the inner race 58 of the bearing |1.

, When it is desired to have the grinding wheel 61-conform to a circularpath, the radius of rotation thereof is determined by the distancebetween the grinding wheel 61 and the pivot post This distanceiscontrolled by locking the articulated joint between the arm member 21and the extension 40. The articulated joint is locked by permitting thespring loaded locating pin 44 to engage in a selected socket 42givingthe desired radius of rotation.

When it is desired, movement of the grinding wheel 61 may be restrictedto movement in apredetermined plane without'the circular limitation. oaccomplish this, the locatinglpin 44 is disengaged from the socket andheld in such disengaged position by inserting the-lockingipin 50 to holdthe l'ocatingpin in retracted position.

When the locatin pin 44 is thus disengaged, the extension 60 is free topivot on the arm member 2? and the predetermined plane of the grindingwheel may be manually traversed at will.

The communication of the driving force through the and shaft arrangementpreviously described from the prime mover to the grinding wheel 6'?permits swivel movement of the spindle 82 and prime mover in relation tothe mounting therefor. This swivel movement permits the convenientmanual manipulation of the grinder and enables grinding to beaccomplished in restricted spaces.

As the grinding of the member I progresses, the grinder is lowered byreadjusting the inner race 18 of the bearing I! on the pivot post I2.

While I have shown but one embodiment of my invention, it is susceptibleto modification without departing from the spirit of the invention. I donot wish, therefore, to be limited by the disclosures set forth, butonly by the scope of the appended claims.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

I claim:

1. An apparatus for use with a portable motor Comprising a spider membercomprising a central body portion having a socket formed therein, aplurality of leg elements radially extended from the body portion,adjustment studs screw-threadedly engaged in the outer ends of the legelements so as to be outwardly extensible; a ball element supported inthe socket of the body portion; a retainin plate secured to the bodyportion to maintain the ball member in the socket; a pivot postsorew-threadedly engaged to the ball member and swivelly supportedthereby; a leveling plate transversely secured circumjacent the pivotpost; a plurality of adjustment studs screw-threadedly engaged in theleveling plate in a position to engage the spider member and incooperation therewith to maintain the pivot post in selected position; aradial arm member; a roller bearing screw threadedly mounted on thepivot post spacially adjustable thereon in relation to the spider memberand rotatably supporting the arm member in a plane substantially atright angles to the pivot post; an articulated joint in the arm memberpermitting the pivoting of the outer end portion of the arm member in aplane substantially parallel to the rotation plane of the arm member;sockets and a spring loaded catch in spaced relation thereto in oppositearm portions to lock the articulated joint at selected points ofadjustment; a grinding wheel; a mounting shaft for the grinding wheel; abearing engaged in the outwardly extended end portion of the arm memberto support the mounting shaft substantially at right angles to the planeof rotation of the arm member; a universal coupling means engaged to themounting shaft; and a coupling member for connecting the universal gearmeans to the driving mean of the motor.

2. A grinder adapted for use with a motor comprising a spider memberhaving extensible leg portions for tightening the spider member in placewithin openings in members whose sur rounding material is to be ground,a universal joint mounted in the spider member, a pivot post swivellysupported by the universal joint, 9.. leveling plate secured to thepivot post in circumjacent relation thereto, adjustment means borne bythe leveling plate for embracing the spider and positioning the pivotpost, a. radial arm member rotatably supported by the pivot post in aplane substantially at right angles to the pivot post, screw threadedmeans on pivot post and arm member for adjusting the height on the pivotpost at which the arm member is permitted to rotate, an articulatedjoint in the arm member permitting the outwardly extended end portionthereof to pivot in a plane substantially parallel to that of therotation of the arm member, a grinding wheel rotatably supported in theoutwardly extended end portion of the arm member, and a universal jointcommunicating between the driving means of the motor and the grindingwheel.

3. In a grinder mounting of the character described, a spider memberhaving extensible leg portions for mounting the spider in openings inmembers whose surrounding material is to be ground, a universal jointmounted in the spider member, a pivot post swivelly supported by theuniversal joint, adjustment means for positioning the pivotpost inrelation to the spider memher, a radial arm member rotatably mounted onthe pivot post to swing in a plane substantially at right angles to thepivot post, means on the pivot post for adjusting the location on thepivot post at which the arm member is permitted to rotate, anarticulated joint in the arm member, a grinding wheel rotatably mountedin the extended end portion of the arm member, and a universal couplingproviding communication between a prime mover and the grinding wheel torotate the grinding wheel in a plane determined by the adjustment of thearm member on the pivot post.

4. A grinder comprising a spider member having extensible leg portions,a pivot post swivelly mounted in the spider member, an arm memberrotatably mounted on the swivel post, means for adjusting the plane ofrotation of the arm member in relation to the spider member, anarticulated joint in the arm member, a grinding wheel supported in theoutwardly extended end portion of the arm member, a driving means forthe grinding wheel, and a universal coupling interposed between thedriving means and grinding wheel permitting freedom of movement of thedriving means while the grinding wheel is maintained in a predeterminedplane.

5. A grinder comprising a mounting means engageable in openings inmembers to be ground, a pivot post swivelly supported by the mountingmeans, a radial arm member rotatably mounted the pivot post, means foradjusting the plane of rotation of the arm member in relation to themounting means, a grinding wheel rotatably supported by the extended endportion of the arm member, means for varying the distance from thegrinding wheel to the pivot post and a driving means supported by thearm member in communication with the grinding wheel.

JOEL S. BLOOD.

